Problem: Wanda is trying to locate the Fermat point $P$ of $\triangle ABC$, where $A$ is at the origin, $B$ is at $(10,0)$, and $C$ is at $(3,5)$ (the Fermat point is the point such that the sum of its distances from the vertices of a triangle is minimized). She guesses that the point is at $P = (4,2)$, and computes the sum of the distances from $P$ to the vertices of $\triangle ABC$. If she obtains $m\sqrt5 + n\sqrt{10}$, where $m$ and $n$ are integers, what is $m + n$?

[asy]
string sp(pair P1, string P2){return "$" + P2 + "\,(" + string(P1.x) + "," + string(P1.y) + ")$";}
size(150);

defaultpen(fontsize(10));

draw((-3,0)--(10,0),Arrows(4));

draw((0,-3)--(0,8),Arrows(4));

pair A=(0,0),B=(10,0),C=(3,5),P=(4,2);

draw(A--B--C--cycle, linewidth(0.7));

draw(A--P, dashed);

draw(B--P, dashed);

draw(C--P, dashed);

label(sp(A,"A"),A,NW);

label(sp(B,"B"),B,S);

label(sp(C,"C"),C,N);

label(sp(P,"P"),P,(-0.5,-2.8));

dot(A); dot(B); dot(C); dot(P);
[/asy]
Solution: By the distance formula,  \begin{align*}
AP &= \sqrt{(4-0)^2 + (2-0)^2} = \sqrt{16 + 4} = 2\sqrt{5} \\
BP &= \sqrt{(4-10)^2 + (2-0)^2} = \sqrt{36 + 4} = 2\sqrt{10} \\
CP &= \sqrt{(4-3)^2 + (2-5)^2} = \sqrt{1+9} = \sqrt{10}
\end{align*}Hence, $AP + BP + CP = 2\sqrt{5} + 3\sqrt{10}$, and $m+n = \boxed{5}$.